Abstract: Diffusion bonding behavior between Ti(C,N)-Al₂0₃ ceramic matrix composites (CMC) and 40Cr steel was investigated using pulse current auxiliary liquid diffusion bonding process. The effect of aided pulse current and holding time during diffusion bonding on the element distribution, phase structure and thickness of the reactive layer at the interface was characterized. The results show that aided pulse current during diffusion bonding promoted the metallurgical bonding between CMC and 40Cr steel. The corresponding joint strength was about 146~180 MPa and was not obviously affected by the holding time during bonding. The diffusion path and rate of atoms at the interface were apparently changed by the loading of pulse current during diffusion bonding. Consequently, the growth of interfacial inter-metallic compounds and the content of low melting point eutectic phases could be controlled to improve the joint strength.